pratt



(No Model.)

N. W. PRATT. MEANS FOR CLOSING TUBES 0F STEAM GENERATORS.

Patented Nov. 10, 1896 awvawto z abfomec% ERS CO PHOTOJJTHD, WASNKNGTON,D C.

wilbneowa w: mama PET NAT w. PRATT,

Y UNITED STATES PATENT OFFICE.

OF BROOKLYN, NEW YORK, ASSIGNOR TO THE BABOOCK & W'ILOOX COMPANY, OF NEWYORK, N. Y.

MEANS FOR CLOSINC TUBES OF STEAM-GENERATORS.

SPECIFICATION forming part of Letters Patent No. 571,016, dated November10, 1896.

Application filed November 23, 1895. Serial No. 569,893. (No model.)

To all whom it may concern:

Be it known that I, NAT IV. PRATT, a citizen of the United States,residing in the city of Brooklyn, county of Kings, and State of NewYork, have invented certain new and useful Improvements in Means forClosing the Tubes of Steam-Generators, of which the following is aspecification.

The object of this invention is to provide means whereby the ends of anyof the watertubes which form a part of the steam-generator may betightly closed should the tube leak or burst at any time, so that theboiler may continue in use until a convenient time shall arrive forrepairing the leak or replacing the tube with another.

To this end the invention consists in providing the headers with whichthe water-tubes are connected with valves or plugs located in alinementwith the longitudinal axes of the tubes, respectively, which valves orplugs are normally held away from the ends of the tubes, so as not toimpede circulation, but are arranged so that they can be forced inwardto close the ends of a leaky or burst tube, as hereinafter described andclaimed.

In the accompanying drawings, Figure 1 represents in vertical section online 00 0c of Fig. 2 a portion of the front header of a sectionalsteam-gen erator embodying the invention with a portion of thewater-tubes connected thereto. Fig. 2 shows in front elevationonasmaller scale a series of such headers, and means which may be usedfor forcing inward the valves or plugs employed to close the ends of thetubes.

A denotes several of the water-tubes which form the main portion of thesteam-generator,

and B are the front headers to which such tubes are connected. In thedrawings only the front headers are shown, but it is to be understoodthat the rear headers are similarly constructed and provided with themeans frusto-conical shape, its smallest diameter being less than andits largest diameter greater than that of the bore of the tube, so thatwhen the valve or plug is forced inward its head will partially enterthe end of the tube and securely close the same.

Preferably each of the valves or plugs O is normally held in a rearwardposition, or away from the end of its tube, by a soft-metal key E, whichpasses through a slot 6 in the valvestem 0 and takes bearing upon theouter face (I of the bushing D. The rear face f of the valve-head andthe inner face (1 of the bushing are preferably ground to form a steamtightj oint, so as to prevent any leakage around the valve-stem. In placeof grinding these parts to form a joint, however, or in additionthereto, a soft packing g may be introduced between the valve-head andthe bushing, as will be readily understood.

hen a Water-tube is found to be leaking and it can be determined whichtube is defective, the valves at the ends of such tube are forced inwardto close the tube,'when the pressure upon the faces f of the valve-headswill hold the valves securely closed until the convenient time arrivesfor making repairs. The forcing of a valve inward to close the end of atube may be effected by a hammer-blow upon the outer end of its stem ofsufficient force to shear off the key E and drive the valve into place.

As it may be extremely difficult in some cases to determine the definitewater-tube which is leaking, means may be provided for forcing inwardall or a series of the valves in the same row, such means beingduplicated, so that all the valves can be operated. Various devices maybe employed for this purpose, as will be readily understood, but thoseshown in the drawings consist of shafts H, upon each of which is aseries of levers or cams h in alin ement with the valve-stems,respectively, each shaft being provided with a lever J or other suitablemeans for turning it. hen a shaft H is turned in the direction of thearrow, Fig. 1, the cams h thereon will be swung upward, thereby shearingoff all the keys E of the valves which said cams are to operate anddriving the valves into their respective tubes. A reverse turning of theshaft will swing the cams outward again and all the valves except theone which closes a leaky tube will be returned to normal position andwill be held there by the pressure in the perfect tubes, while the valvewhich closes the leaky tube will be held closed, as hereinbeforedescribed. The returned valves may then be keyed up again whenopportunity permits.

It will be readily seen by any skilled mechanic that several of theshafts H may be geared or connected together and the cams thereon be soarranged as to force inward a large number of the valves at the sametime, sufficient power being applied for the "purpose.

What I claim as my invention, and desire to secure by Letters Patent,is-

l. The combination, with the headers of a sectional steam-generator, ofvalves or plugs loosely mounted in the outer faces of said headers andin alin ement with the'longitudinal axes of the water tubes of thegenerator and adapted to slide inwardly and close the ends of thepipes,substantially as and for the purpose specified.

2. The combination, with the headers of'a sectional steam-generator, ofvalves or plugs loosely mounted in the outer faces of said headers inalinement with the'longitudinal axes of'the water-tubes.and'adapted toslide inwardly and-close the ends of the pipes and means for holdingsaid valves or .plugs in rearward, normal position, substantially as setforth.

3. The combination, with the headers of a sectional steam generator, ofbushings or plates secured to their outer faces; valves or plugspassingthrough said'bus'hings or plates in alinement with thelongitudinal axes of the water-tubes; and keys passing through saidvalves, for holding the same in normal position, substantially as setforth.

4:. The combination, with theheaders of a sectional steam-generator, ofvalves or plugs loosely mounted in the outer faces of said headers in'alineme'nt with the longitudinal axes of the water-tubes of thegenerator, and means for forcing'a series of said valves inward atthe-same time, substantiallyasand for the ,purpose specified. v

5. The-combination, with theheaders of-a sectional steam-generator, ofvalves or -.plugs looselymounted in theouter faces thereof in alinementwith the longitudinal axes of the water-tubes of the gen erator; aseries of shafts bearing levers or cams in'alinement with the valves;and means for rotatingsaid shafts, substantially as and for thepurposespecified.

. NAT \V. PRATT.

\Vitnesses;

O. W. FoRBEs, CHAS. lIAN-lMANN.

